As technology has advanced, portable terminals have begun to be used as multimedia devices supporting functions such as schedule management, games, remote control, and image capturing. In particular, advanced portable terminals may provide touch screens for data input along with various user interfaces for operating the touch screens. Moreover, some portable terminals provide stylus pens for interacting with the touch screen user interfaces. When a stylus pen is used, touch screens can be controlled more finely than with a user's finger. For this reason, the popularity of stylus pen-enabled portable terminals is increasing.
In addition to touch screens, portable terminals provide physical buttons for controlling aspects of their operation, such as a volume increase/decrease buttons, power on/off buttons, mute buttons, and others. Such buttons may be mechanically actuated, and may require to be pressed (or otherwise touched) by the user in order to be activated. When a stylus pen is used, the user often cannot grasp the stylus pen and interact with the physical buttons at the same time. Accordingly, to interact with the physical buttons, the user has to first lay down the stylus pen and then manipulate the physical buttons. This, however, may disrupt the user's interactions with the portable terminal and be a source of inconvenience to the user.
Accordingly, the need exists for improved user interfaces for controlling the operation of portable terminals.